[Qemu-devel] [Bug 654913] Re: Windows XP uses 200% CPU when given 2 VCPUs

[Michael Tokarev]

WinXP chews 200% CPU when switched in device manager to "MPS computer"
from "ACPI computer" even if there's no -no-acpi on the kvm command line
(after some tries I was able to switch it from ACPI to MPS).  So it is
how windows works, not how kvm works.

** Changed in: qemu
       Status: New => Invalid

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Windows XP uses 200% CPU when given 2 VCPUs
https://bugs.launchpad.net/bugs/654913
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Status in QEMU: Invalid

Bug description:
When using libvirt to give a domain 2 CPUs (<domain 
type='kvm'><vcpu>2</vcpu></domain>), the Windows XP kvm process will use 200% 
CPU when Windows is idle. Switching the number of CPUs back to 1, the kvm 
process gives normal idle percentages.

Using libvirt 0.8.3-1ubuntu9, tried with the following qemu-kvm packages:

qemu-kvm_0.12.4+noroms-0ubuntu7_amd64.deb
qemu-kvm_0.12.5+noroms-0ubuntu4_amd64.deb

The smp flag being set by libvirt is:

-smp 2,sockets=2,cores=1,threads=1